Method of making packaging materials



Sept. 10, 1957 A. P. KLASlNG EI'AL METHOD OF MAKING PACKAGING MATERIALS 2 Sheets-Sheet 1 Filed May 14, 1954 FIG-2 NVENTORS KLASING RIC E ATTORNEY a ARTHUR WILLIAM J. BY

Sept. 10, 1957 A. P. KLASING ETAL 2,305,973

METHOD OF MAKING PACKAGING MATERIALS 2 Sheets-Sheet 2 Filed May 14, 1954 INVENTOR. ARTHUR P. KLASING WILLIAM J. RIC E ATTORNEY.

United States Patent METHOD OF MAKING PAtIKAGING MATEREALS Arthur P. Klasing, Webster Groves, and -William 3. Rice, University City, Mo., assiguors to Central States-Paper & Bag Co., St. Louis, Mo., a corporation of Ivlissouri Application May 14, 1954, Serial No. 429,853 3 Claims. (Cl. 154-83) This invention relates in general to tubing, bags, and similar fabricated materials for enclosing articles capable of being packaged and, more particularly, to certain new and useful improvements in such packaging materials and in means and methods of making the same.

It is the primary object of the present inventionto. provide means for fabricating thermoplastic synthetic resin films, such as polyethylene and the like, into packaging materials, such as bag-forming tubing and bags made from such tubing.

It is another object of the present invention to provide means and methods for manufacturing packaging materials of the type stated from thermoplastic synthetic resin films in a highly economical, continuous, eflicient and rapid manner.

It is a further object of the present invention to provide a packaging device in the nature of a bag which is uniquely adapted for enclosing meat, poultry, or any other articles of merchandise suitable for display and sale in retail shops, department stores, supermarkets, and the like.

With the above and other objects in view, our invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawings (two sheets) Figure l is a schematic view of machinery embodying the present invention and being adapted for making bagforming tubing from thermoplastic synthetic resin films;

Figure 2 is a fragmentary sectional view taken along line 22 of Figure 1;

Figure 3 is a schematic view of machinery embodying the present invention and being adapted for making bags out of the bag-forming tubing;

Figure 4 is a plan View of a bag constructed in accordance with and embodying the present invention;

Figure 5 is a transverse sectional view taken along line 55 of Figure 4; and

Figure 6 is a fragmentary sectional view taken along line 6-6 of Figure 4.

Referring now in more detail and by reference characters to the drawings, which illustrate a preferred embodiment of the present invention, A designates a tube-.

forming machine which comprises two supply-shafts 1, 2, for respectively supporting rolls 3, 4, of thermoplastic synthetic resin films, such as polyethylene or the like, and from which two separate continuous webs w, w, of film may be withdrawn, the webs w, w, preferably, though not necessarily, being of equal width and arranged in marginal registration. Operatively mounted in spaced parallel relation to the supply-shafts 1, 2, are tensioning rolls 5, 6, around which the webs w, w, are respectively trained and brought into facewise marginally registered abutment for passage between a first pair of co-operating feed rolls 7, 8, which are also disposed in parallel relation to the shafts 1, 2. Similarly mounted in spaced parallel relation to the feed rolls 7, 8, and forwardly therefrom along the path of travel of the combined webs w, w, is a large diameter platen-roll 9 and a second pair offeed rolls 10, 11. Operatively mounted beyond the second pair of feed rolls 10, 11, are separate rewind-shafts 12, 13. The bearings for the shafts 1, 2, 12,13, the adjustable trunnions for the tensioning rolls 5, 6, the gear-drive for Fa -tented Sept. 1Q, 1957 .,not been shown inasmuch as such elements are conventional and well understood in connection with winding and reeling machinery. it is merely sufiicient for present purposes-to note that the driving and web-tensioning mechanism should co-act and co-operate to keep both webs w, w, taut without breaking and moving together at identical lineal speed so as to pass around the platen-roll 9 in snug unwrinkled contact against the surface thereof.

Rigidly mounted in outwardly spaced parallel relation to the platen-roll 9 is a dovetail bar 14 for supporting a plurality of electrically or electronic heated sealers 15, each including a base-block 16 having a dovetail slot 17 for sliding engagement with the bar 14 and being provided with a set-screw 18 for locking engagement with the bar 14, so that the sealer 15 can he slid along the bar 14 to any desired position of adjustment to accommodate the width of the webs w, w, and then tightly secured in such adjusted position. Secured to the base-block 16 by means of adjusting screws 19, 19', is a sealer-bar 20 provided at its outer end with a wedge-shaped sealer-head 21 internally equipped with a conventional resistance-type electric heating element 22 and having a narrow somewhat rounded sealing edge 23. The sealer-bars 20 may be respectively.

adjusted inwardly or outwardly with respect to the baseblocks 16 by appropriate setting of the screws 19, 19', so that the outer sealers 15 will press the registering edges of the webs w, w, down with sufficient pressure and temperature to fuse them together. The central sealer 15 is adjusted so as to be practically in contact with the surface of the platen-roll 9 and slit and seal the webs w, w, at the same time, as shown in Figure 2, thereby forming two continuous webs of edge-sealed flat tubing 2, which are separately rolled up on the rewind-shafts 12, 13, It will, of course, be understood that by using more than one intermediate sealer 15, it is possible to form more than two webs of tubing.

Bags can be formed from the rolls of tubing thy placing one of such rolls upon an unwind shaft 24 and feeding the tubing 2 preferably in a horizontal direction between intermittently driven feed rolls 25, as, and beneath a vertically reciprocating cutting-blade or knife 27 adapted to cut the tubing t into sections of desired length. Operatively mounted along the path of travel of the tubing t forwardly with respect to the knife 27 is a flat platen 28 and a vertically reciprocating electrically heated die-plate 29 adapted to sever and seal the sections along an arcuate line in the provision of a bottom seam s and thereby forming the section into a completed bag B. interposed between the flat platen 28 and the knife 27 is an accelerating transfer-belt 30 for shifting each cut section forwardly onto the platen Z8 beneath the die-plate 29. The driving mechanism for the rolls 25, 26, the knife 27, the die-plate 29 and the transfer-belt 30 is entirely conventional and is, therefore, not shown, but it is sufficient for purposes to point out that the entire mechanism operates intermittently,

so that successive lengths of tubing are fed beneath the knife 27- and during the dwell in the feeding movement the knife 27 is shifted downwardly to sever the tubing and thus cutoff a bag-forming section.

Thereupon, the cutoff section is fed by the transfer-belt 3t beneath the die- 7 plate 29 and during the dwell in this feeding movement the feed rolls 7, 8, '10, 11, and the platen-roll 9 have V the die-plate 29 is shifted downwardly to complete the bag B. The crescent-shaped strip of excess material e, of course, may be discarded as scrap. By suitable variation in the shape of the rule on the die-plate, and the position thereof in relation to the opposite ends of the cut-off sections, it is possible to form two bags at once.

The completed bag B thus comprises two overlying identically shaped panels 31, 32, secured together along' their longitudinal margins and across the bottom by a continuous and uninterrupted heat-sealed seam 33, which consists in part of the seam s formed by the die-plate meats, poultry, and the like, since such food products can be placed in such a bag with the more attractive sides presented toward the transparent panel 31 and the visceral or less attractive sides toward-theopaque panel 32. The bag B, when completed, has a wide mouthed or open top, so that such food products can be readily disposed th'erein. When suitably filled, the bag B can be heat-sealed, stapled shut, or otherwise conventionally closed.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the packaging materials and means and methods of making the same may be made and substituted for those herein shown'and described without departing from the nature and principle of our invention.

Having thus described our invention, what we claim and desire to secure by Letters Patent is: V

1. The method of making a flat container which comprises unwinding two webs of thermoplastic film which are capable of fusing together under heat, passing said webs in marginally registering superposed relation over 'a roller, applying heated knife edges to the margins of said webs as said margins pass over said roller to thereby seal them together in a narrow marginal seam, and applying a heated knife edge to the web at a position intermediate the edge-seal forming elements and thereby simultaneously slitting the web and sealing both sides of the slit, thereby forming the web into a plurality of parallel continuous tubes, severing the tube thus formed into sections of selected length, and sealing one transverse margin of each such section to form an open mouth envelope-typebag.

2. The method of making a container which comprises unwinding two webs of thermoplastic film which are capable of fusing together under heat, passing said webs in marginally registering superposed relation over a roller under tension, applying heated knife edges to the margins of said webs as said margins pass over said roller to thereby seal them together in a narrow marginal seam, and applying a heated knife edge to the web at a position intermediate the edge-seal forming elements and thereby simultaneously slitting the web and sealing bothsides of the slit, thereby forming .the web into a plurality of parallel continuous tubes, severing the tube thus formed into sections of selected length,

and sealing one transverse marg'in of each such sec-' tion to form an open mouth envelope-type bag.

3. The method of making a bag which comprises continuously unwinding two webs of thermoplastic film having'substantially similar chemical composition and which are capable of fusing together under heat, passing said webs in marginally registering superposed relation over a cool roller, applying heated knife edges to the margins of said webs as said margins pass over said I roller to thereby seal them together in a narrow marginal seam, and applying a heated knife edge to the web at a position intermediate the edge-seal forming elements and thereby simultaneously slitting the web and sealing both sides of the slit, thereby forming the web into a plurality of parallel continuoustubes, severing the tube thus formed into sections of selected'length', and sealing one transverse margin of each such section to form an open mouth envelope-type bag.

3 4. Themethod of making a flat container which comprises unwinding two webs of thermoplastic filmrhaving substantially similar chemical, composition and which are capable of fusing together under heat, passing said 50 bag.

5 plying a heated knife edge to the web at a position intermediate the edge-seal forming elements and thereby simultaneously slitting the Web and sealing both sides of the slit, thereby forming the web into a plurality of parallel continuous tubes, severing the tube thus formed into sections of selected len th and formin an arcuate heat seal across one transverse margin of each section.

5. The method of making bag tubing which comprises unwinding two webs of, thermoplastichlm which are capable of fusing together under heat, passing said webs in marginally registering superposed relation over a roller,

applying heated'knife edges to the margins of said webs as said margins pass over said roller to thereby seal them together in a narrow marginal seam, and applying'a heated knife edge to the Web at a position intermediate the edgeseal forming elements and thereby simultaneously slitting the web and sealing both sides of the sht, thereby forming the web into a plurality of parallel continuous tubes.

6. The method of making bag tubingwhich comprises unwinding two webs of thermoplastic film which are capable of fusing together under heat, passing said webs in marginally registering superposed relation over a roller under tension, applying heated knife edges to the margins of said webs as said margins pass over said roller to thereby seal them together in a narrow marginal seam, and

applying a heated knife edge to the web at a position intermediate the edge seal forming elements and thereby simultaneously'slitting the web and sealing both sides of the slit, thereby forming the web into a plurality of parallel continuous tubes.

7. The method of making a fiat container which comprises unwinding two webs of thermoplastic film which are capable of fusing together under heat, passing said webs in marginally registering superposed relation over a roller, applying heated knife edges to the margins of said webs as said margins pass over said roller to thereby seal them together in a narrow marginal seam, and simultaneously applying a heated knife edge to the web at a position intermediate the edge-seal forming elements and thereby slitting the web and sealing both sides of the slit, thereby forming the web into a plurality of parallel continuous tubes, severing the tube thus formed into sections of selected length, and sealing one transverse margin of each such section to form an open mouth envelope-type 8. The method of making bag tubing which comprises unwinding two webs of thermoplastic film which are capable' of fusing together under heat, passing said webs in marginally registered superposed relation over a roller,

applying relatively narrow heat-sealing elements to the margins of said webs as said margins pass over said roller to thereby seal them together in a narrow marginal seam, and applying a narrow heat-sealing element to the web at a position intermediate the edge-seal forming elements continuous tubes.

References Cited in the file of this patent UNITED STATES PATENTS 3 2,257,823 Stokes Oct. 7, 1941 2,409,100 Brady Oct. 8, 1946 2,444,685 Waters -a July 6, 1948 2,466,387 Curtis Apr. 5, 1949 1 2,623,689 -WilcoX Dec. 3:0, 1952 2,623,681 Wilcox "p66. 30, 1952 2,645,591 Makrauer luly 14, 1953 2,679,280 'Marsh May 25, 1954 2,740,740 Binnall Apr; 3, 1956 2,749,817 Piazze et. 1 June 12, 1956 and thereby forming the web into a plurality of parallel 

1. THE METHOD OF MAKING A FALT CONTAINER WHICH COMPRISES UNWINDING TWO WEBS OF THERMOPLASTIC FILM WHICH ARE CAPABLE OF FUSING TOGETHER UNDER HEAT, PASSING SAID WEBS IN MARGINALLY REGISTERING SUPERPOSED RELATION OVER A ROLLER, APPLYING HEATED KNIFE EDGES TO THE MARGINS OF SAID WEBS AS SAID MARGINS PASS OVER SAID ROLLER TO THEREBY SEAL THEM TOGETHER IN A NARROW MARGINAL SEAM, AND APPLYING A HEATED KNIFE EDGE TO THE WEB AT A PORTION 